Electronic devices, including portable electronic devices, have gained widespread use and may include components for providing a variety of functions including, for example, telephonic, electronic messaging and other data manager (PDM) application functions, cellular, wireless 802.11 or Bluetooth™ capabilities, user interface and display functions. Components also may include sensors in the device which provide data about the environment, location or activity, of the device or a combination thereof. Electronic devices include, for example, several types of mobile stations such as simple cellular telephones, smart telephones, wireless personal digital assistants (PDAs) and laptop computers.
Components may be comprised of a dedicated or shared piece of hardware or circuitry within the electronic, a computer software program executed by the electronic device or a combination of hardware and software. Components may include, for example, a touchscreen display; ambient light sensors; temperature sensors; tilt sensors; accelerometers; altimeters; capacitive touch sensors; cameras; pedometers; force sensors to measure force on a display or input of the device; magnetometers to provide a compass heading and gyroscopes to measure angular velocity. Components also may include subsystems or modules in the device including, for example, global positioning systems (GPS) subsystems; cellular communications subsystems which, for example, may provide a cell area location of the device in a cellular network; Internet protocol (IP) communications subsystems; short range communications subsystems; or near field communications (NFC) subsystems.
Power for electronic devices typically is provided by a device battery or a rechargeable power supply and thus is limited. Depending on the number and types of components in an electronic device, power consumption by components may be significant. Power consumption may be managed or limited by managing the activation of components. However, keeping components in a disabled or lower power state may disrupt the operation of the device and may cause delay in the performance of device functions. The delay may be noticeable to the user as components are changed from a disabled or low-power state to an enabled or higher power state.
Like reference numerals are used in the drawings to denote like elements and features.